Pluripotent stem cells such as human embryonic stem cells (hESCs) have the ability to differentiate into any of the three germ layers, giving rise to any adult cell type in human body. This unique property provides a potential for developing new treatments for a number of serious cell degenerative diseases, such as diabetes, spinal chord injury, heart diseases and the like. However there remain obstacles in the development of such hESC-based treatments. Such obstacles include obtaining and maintaining adequate numbers of undifferentiated hESCs in cell and tissue culture and controlling their differentiation in order to produce specific cell types. Stem cell cultures, such as hESC cell cultures are typically seeded with a small number of cells from a cell bank or stock and then amplified in the undifferentiated state until differentiation is desired for a given therapeutic application. To accomplish this, the hESC or their differentiated cells are currently cultured in the presence of surfaces or media containing animal-derived components, such as feeder layers, fetal bovine serum, or MATRIGEL®. These animal-derived additions to the culture environment expose the cells to potentially harmful viruses or other infectious agents which could be transferred to patients or compromise general culture and maintenance of the hESCs. In addition, such biological products are vulnerable to batch variation, immune response and limited shelf-life.
To date, a completely animal product free system employing a chemically defined medium and a synthetic surface has not yet been identified for supporting long-term culture of undifferentiated stem cells.